package com.umessage.hotel.util;

import org.apache.commons.codec.binary.Base64; 
import javax.crypto.BadPaddingException; 
import javax.crypto.Cipher; 
import javax.crypto.IllegalBlockSizeException; 
import javax.crypto.NoSuchPaddingException; 
import javax.crypto.spec.IvParameterSpec; 
import javax.crypto.spec.SecretKeySpec; 
import java.io.UnsupportedEncodingException; 
import java.security.*; 
import java.security.spec.InvalidParameterSpecException; 

/**
 * 解密工具类
 * @author zmj
 *
 *
 *  * Created by lsh  * AES-128-CBC 加密方式  * 注：  * AES-128-CBC可以自己定义“密钥”和“偏移量“。
 *  * AES-128是jdk自动生成的“密钥”。  
 */
public class AesCbcUtil {

	static { 
		//BouncyCastle是一个开源的加解密解决方案，主页在http://www.bouncycastle.org/ 
		Security.addProvider( new org.bouncycastle.jce.provider.BouncyCastleProvider());
  }

	public static String decrypt(String data, String key, String iv, String encodingFormat) throws Exception { 
//    initialize(); 
 
	//被加密的数据 
	byte[] dataByte = Base64.decodeBase64(data); 
	//加密秘钥 
	byte[] keyByte = Base64.decodeBase64(key); 
	//偏移量 
	byte[] ivByte = Base64.decodeBase64(iv); 
 
 
	try{ 
	  Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding"); 
	 
	  SecretKeySpec spec = new SecretKeySpec(keyByte, "AES"); 
	 
	  AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES"); 
	  parameters.init(new IvParameterSpec(ivByte)); 
	 
	  cipher.init(Cipher.DECRYPT_MODE, spec, parameters);// 初始化 
	 
	  byte[] resultByte = cipher.doFinal(dataByte); 
	  if (null != resultByte && resultByte.length > 0) { 
		  String result = new String(resultByte, encodingFormat); 
		  return result; 
	  } 
	  return null; 
	} catch (NoSuchAlgorithmException e) { 
			e.printStackTrace(); 
	} catch (NoSuchPaddingException e) { 
			e.printStackTrace(); 
	} catch (InvalidParameterSpecException e) { 
			e.printStackTrace(); 
	} catch (InvalidKeyException e) { 
			e.printStackTrace(); 
	} catch (InvalidAlgorithmParameterException e) { 
			e.printStackTrace(); 
	} catch (IllegalBlockSizeException e) { 
			e.printStackTrace(); 
	} catch (BadPaddingException e) { 
			e.printStackTrace(); 
	} catch (UnsupportedEncodingException e) { 
			e.printStackTrace(); 
	} 
 
return null; 
  } 
}